Figure 3

The S379A mutant hnRNPK promotes MDA-MB-231 cell migration in an Aurora-A-independent manner. (a) MDA-MB-S379A cells exhibit higher migration ability than the other cell lines. A comparison of cell migration ability among MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells was performed. A total of 3 × 10⁴ MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells were individually seeded into Transwells. After 20 h, the migrated cells were fixed using 10% formaldehyde and stained with crystal violet for image analysis. (b) Measurement of the migration abilities of MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells. Migrated cells in above migration assays were analyzed by ImageJ software. Bar graphs of the cell numbers per field for all three types of cells are reported. Data is shown as mean ± SD, and * indicates significant difference compared to wild type (*p < 0.05 and ***p < 0.001, n = 7). (c) MDA-MB-S379A cells show higher cell migration ability using a wound healing assay than either the control MDA-MB-WT cells or the MDA-MB-S379D cells. A total of 5 × 10⁵ MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells were independently seeded into a 6-well plate and incubated for 24 h. This was followed by scratching an area with fixed width on the plate using a 10 μL tip. The three types of cell were allowed to proliferate and migrate into the scratched area. The migrated cells were photographed using a microscope at 24 h or 48 h after the scratch was created. (d) Comparison of the cell migration abilities of MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells upon inhibition of Aurora-A. A total of 3 × 10⁴ MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells were independently seeded into Transwells for migration assays in the presence of DMSO (control) or of 1 μM of AAI. After 20 h, the migrated cells were fixed using 10% formaldehyde and stained with crystal violet for image analysis. (e) Measurement of the migration abilities of MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells on inhibition of Aurora-A. Bar graphs of the relative fold changes in migrated cells per field for MDA-MB-WT, MDA-MB-S379A and MDA-MB-S379D cells in the presence of DMSO (control) or AAI are reported. Data is shown as mean ± SD, and * indicates significant difference compared to wild type (*p < 0.05, n = 3).